Documenting the first flight carrying airmail between two U.S. cities, these days are now basically over as far as philatelic remembrances, as there is no longer much novelty or interest in new flight routes as there was in earlier years. While the U. S. Postal Service no longer does "first flights" as far as postal documentation thereof, there remains an abundance of these items in philatelic bourses, shows, on-line auctions and flea markets across the country. There is also a specialized group of collectors who look for these items and collect them: The American Air Mail Society.
If you get a chance, be sure to visit the National First Day Cover Museum if you are in Cheyenne, Wyoming. Covers a collector would die for! I visited it in 1987 and it was one of the highlights of my collecting "career". Can anyone verify for me that it is still in existence? Haven't been able to find anything on it in internet searches; it may now be defunct.
Challenger Cover; Carried into Space
1983
Another popular area of collecting right now (especially after the hit movie "Apollo 13") is the collecting of space covers.
Visit my old friend Joe Frasketi's site at http://spacecovers.com/basics.htm
Watch here for an enhanced section on first flights and aero-philately, including space related items, as time permits. Joe is also an excellent resource for information about Local Posts, having had one of his own for years in Florida.
Local Posts- hey, there's a whole 'nuther page... I have some brief mention of local posts on a sub-page of my main polar philately page; look for the link to "Polar Bear Local Post". I also offer servicing of collector-prepared, prestamped cards or covers from my own local post [Spring River Local Post] upon request, at no charge, worldwide.